Index tables are well known in the prior art and provide a convenient method for performing multiple operations on a single or a plurality of components. These operations can include machining operations, assembly operations, gauging operations or any other type of manufacturing operation. Typically, an index table is designed to rotate a specified number of angular increments between a loading station and an unloading station with these two stations being positioned adjacent one another or in some cases, the loading station and the unloading station are located at the same position. In between the loading and unloading station are one or more manufacturing stations located circumferentially around the index table.
A first component is loaded onto the index table in an appropriate fixture at the loading station. If desired, and if the cycle time of the machine allows, as mentioned above, the loading station can also serve as the unloading station. If the loading and unloading station are combined, a finished component would be unloaded from the appropriate fixture prior to the commencement of the loading operation. Once the loading operation and the other various operations around the table have been complete, the table is indexed to place the first component at a station which performs the first operation. While this first operation is being conducted on the first component, a second component is loaded at the adjacent loading station. The table is again indexed and the first component is placed at a station which performs the second operation. While the second operation is being performed on the first component, the first operation is being performed on the second component while a third component is being loaded in a fixture at the loading station. This sequence continues until the first component reaches the unloading station where the finished component is removed. Thus, with each indexing of the table, a completed component is unloaded, a new component is loaded and each station is simultaneously performing its operation on a different component. Depending on the space required for the machinery and/or the number of operations required, an index table will typically cycle anywhere from four to sixteen times in order to complete one turn or one 360.degree. rotation of the index table although the index table can be designed to provide as many or as few stations as the process will require.
When the index table is indexed to each station, it is critical that the location of the index table be accurately controlled to properly locate the component with respect to the machinery at each station in order to provide a consistent and repeatable operation on every component. In addition, the speed with which the table rotates must be kept to a maximum in order to improve the productivity of the operation. While the index table is moving, there are no operations being performed on any component. Thus by keeping the index time to a minimum, the productivity of the index table is improved.
Index tables of various designs have enjoyed wide acceptance in the manufacturing community. The continued development of these index tables is directed towards providing a more reliable and accurate index table while improving upon the performance characteristics of the entire index table system.